Localization of MYOC transcripts in human eye and optic nerve by in situ hybridization

Invest Ophthalmol Vis Sci. 2000 Oct;41(11):3420-8.

Abstract

Purpose: To evaluate MYOC (myocilin) gene expression at the RNA level in normal intact human eyes and optic nerve using in situ hybridization.

Methods: Normal human eyes and optic nerves from donors 62 to 83 years of age with no history of glaucoma were fixed, embedded in paraffin, and sectioned. Sections were hybridized with (35)S-labeled sense and antisense riboprobes derived from a full-length MYOC cDNA.

Results: High levels of MYOC expression were observed throughout the trabecular meshwork as well as in the most anterior nonfiltering meshwork (Schwalbe's line), in the scleral spur, and in the endothelial lining of Schlemm's canal. MYOC transcripts were also detected in the anterior corneal stroma, in the ciliary muscle, beneath the anterior border of the iris, in the iris stroma, and in the sclera. Expression in the retrolaminar region of the optic nerve was present in the pial septa that divide the nerve fiber bundles, in the perivascular connective tissue surrounding the central retinal vessels, and in the dura mater, arachnoid, and pia mater of the meningeal sheath surrounding the optic nerve.

Conclusions: MYOC gene expression in the trabecular meshwork, Schlemm's canal, scleral spur, and ciliary muscle indicates a structural or functional role for myocilin in the regulation of aqueous humor outflow that may influence intraocular pressure. MYOC expression in the optic nerve suggests that changes in the structural, metabolic, or neurotropic support of the optic nerve may influence its susceptibility to glaucomatous damage.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Blotting, Northern
  • Ciliary Body / metabolism*
  • Cytoskeletal Proteins
  • Endothelium / metabolism
  • Eye Proteins / biosynthesis
  • Eye Proteins / genetics*
  • Gene Expression
  • Glycoproteins / biosynthesis
  • Glycoproteins / genetics*
  • Humans
  • In Situ Hybridization
  • Middle Aged
  • Muscle, Smooth / metabolism*
  • Optic Nerve / metabolism*
  • RNA, Messenger / biosynthesis*
  • Sclera / metabolism
  • Trabecular Meshwork / metabolism*

Substances

  • Cytoskeletal Proteins
  • Eye Proteins
  • Glycoproteins
  • RNA, Messenger
  • trabecular meshwork-induced glucocorticoid response protein